HELP !!!! got intermittent warning saying CHARGING SYSTEM FAULT brand new batteries fitted last week i have reset the BMS when engine is running multimeter tells me its charging at 14.8 volts but when i put the meter on auxillary battery just stays at 12 volts as if there is no charge going into it ? anyone got an idea what could be going on CHEERS GUYS also stop start function not working

 

Can you get the car scanned with a working SDD system?
Without information/codes we won't be able to help?

Plus without any car information it makes it even harder?
.
.
.

 

car is 2013 xj 3.0 diesel dont have access to sdd i have used my car isoft diagnostics scanner but it doesnt show any faults or codes !!!! maybe have to invest in a sdd

 

With the ignition in the OFF position, use a voltmeter to check available voltage across the main battery terminals. There should be a minimum of 12.6 volts present. Age of the battery is immaterial.

Bear in mind the charging system is controlled by the ECM/PCM, so output from the alternator is not constant.

How many kilometres/miles are on the vehicle?

 

will do that at weekend mate the car has done 65000 miles

 

mike , think ive got this , yours is the old type so to speak with the ancillary small battery , this Do not feed from the main battery , so you have to also charge this up to 12,6 volts , mine the 66 version has only the big battery and i replaced this myself only for a few error codes through up and car would not start , in the end i had to call out jaguar assist who told me battery has to be tuned in by them with their diagnostics , hopes this helps , george

 

Again incomplete information is not helping?
EXACTLY what battery did you install? ALL the details.
Was it the proper AGM type? What size? You mention batteries? Did you replace both of them?
.
.
.